Friday, May 29, 2009 launches

The Geek Atlas is not just a book, it's also a web site. Over on The Geek Atlas web site you'll find information that complements the book such as photos, videos and trip reports.

And it's intended to be a community effort. Have you been to one of the places in the book? How about uploading your pictures or video? Or write a trip report.

Did I miss a place that really should have been in the book? Jump into the forums and post about it. If I get enough ideas perhaps there'll be a second edition :-)

Has something changed about a place (such as opening hours, cost, etc.). Come tell me (and the community about it).

It's as much your web site as it is mine. Drop by

Wednesday, May 27, 2009

Five places you've never heard of featured in The Geek Atlas

The Geek Atlas includes some of the big, famous science attractions around the world, but it's also about places that you haven't heard of, and shouldn't miss.

Have you ever visited these?

1. Experimental Breeder Reactor 1 near Arco, Idaho.

It's the first ever breeder reactor and in its parking lot there are two nuclear aircraft engines (that, happily, never got off the ground). And it's free. If you are a nuclear tourist then this is the place to go: it's got the first lightbulbs lit with nuclear power.

2. The International Latitude Observatory in Gaithersburg, Maryland

If you're an astronomer making accurate observations of the stars from an Earthly observatory then knowing how the Earth rotates is essential. This observatory was one of a chain that accurately followed Earth's rotation and all its weird and wonderful wobbles.

3. The Fermat Museum in Beaumont-de-Lomange, France

Pierre de Fermat is known for his Last Theorem which was only proved hundreds of years after his death. He lived in this market town in France which is full of delicious local produce and a museum of his life and mathematics with lots of mathematical games for people of all ages.

4. The nuclear bunker at The Greenbrier in West Virginia

If the US were involved in a nuclear war there needed to be a place for the entire US Congress to keep working. That place was underneath one of the most luxurious resorts in the US. The secret's now out and the bunker is decommissioned and open to the public.

5. The Mendel Museum of Genetics in Brno, Czech Republic

Gregor Mendel was the monk who figured out the fundamental laws of inheritance of traits by children from their parents by observing generation after generation of pea plants. Years before genes were understood, Mendel had made observation and deductions that identified how traits are paired with recessive and dominate versions.

You won't find the places in The Geek Atlas just by asking at a tourist office. It's abut the places that matter in science and then tourism has forgotten.

Tuesday, May 26, 2009

The Geek Atlas video series

Craig Smith over at O'Reilly GMT recorded a set of videos of me talking about The Geek Atlas inside the Royal Institution's museum. He'll be releasing those videos via YouTube in the coming days.

The first such video is now online. Here I am talking about Chapter 096 (Experimental Breeder Reactor 1):

Thursday, May 21, 2009

The Geek Atlas is now available as an ebook

If you can't wait any longer for The Geek Atlas it's now available as an ebook for iPhone, PDF, Kindle and Sony Reader.

It's also available to anyone with a Safari subscription:

Wednesday, May 13, 2009

Taking a fresh look at familiar landmarks with The Geek Atlas

Three of the places in The Geek Atlas are probably familiar to many people: the Atomium in Brussels, the Eiffel Tower in Paris and the Gateway Arch in St. Louis, MO.

So you might ask yourself why I included them. The answer is that all three have real scientific interest.

The shiny Atomium is actually in the shape of an iron crystal. More interestingly it's the shape of just one of the allotropes of iron (the different structures that iron can form). Allotropes are very important because they show how a simple element like carbon can form graphite, diamonds and other more exotic structures.

The Eiffel Tower's shape was determined by Gustav Eiffel by calculating the effect of the Parisian wind on such a tall structure (at the time it was the tallest building in the world). And Eiffel managed to make it tall and fragile looking by calculating which pieces of iron he could remove.

The Gateway Arch is an example of a catenary arch. A catenary is a natural shaped formed just by the force of gravity. If you hold a piece of string with its ends in each hand and then hold your hands level the string falls to form a graceful catenary curve.

Details of these three places, the science behind them, and one more surprise about The Eiffel Tower (for which you'll probably want a pair of binoculars) are in the book.

Some of the science inside The Geek Atlas

The Geek Atlas is not just about travel, it's also about the science behind the places that are worth visiting. Every place has an accompanying sidebar of one to three pages covering a relevant scientific, mathematical or technological topic.

The sidebars vary in complexity from the simple to the really complex. Every reader should find something to please them in the scientific sidebars and no one should feel ashamed if they decide to skip a piece of science that's too complex. Even if you never read a single sidebar you'll still enjoy The Geek Atlas because every place has a description that's ready to be digested by any reader.

But do delve into the sidebars where you can find out about things like:

1. How the Big Bang was accidentally verified using a large horn shaped antenna in New Jersey, and why the Big Bang is still sending out microwave radiation.

2. Archimedes' Principle and how it applies to the everyday problem of moving boats between canals of different heights.

3. How Charles Babbage's Difference Engine works and the mathematics behind it.

4. Alan Turing's proof that no computer can predict whether a computer program will work or not.

5. Why the cable on a suspension bridge forms the shape of a parabola.

6. How the human genome, and other genomes, are sequenced.

7. The chemical reactions that happen inside a coke blast furnace to produce high quality iron (which helped get the Industrial Revolution moving).

8. How the gasoline and diesel engines work and how they differ.

9. How the transistor is used to build up the basic bits of logic needed to make a computer.

10. What the human body's lymphatic system does and how it works.

And that's just 10 of 128 pieces of science that sit along side the 128 places worth visiting in the book.

Tuesday, May 12, 2009

Children and The Geek Atlas

An obvious question for parents who are thinking of getting The Geek Atlas is "are any of these places suitable for children?". That question is answered in the book with a little icon next to places that I think are suitable for kids.

For example, some of the great museums are really good for kids. No child should be denied a visit to London's Natural History Museum (place 061 in the book), and the National Air and Space Museum in Washington, DC is also wonderful (it's place 092). And everyone aged 9 or 99 needs to visit the Kennedy Space Center (place 094).

But some of the lesser known places are also really good for kids. The Falkirk Wheel in Scotland (place 072) is scientifically interesting (there are exposed cogs and a chance to talk about Archimedes' Principle) and you get a boat ride thrown in.

The Sagan Planet Walk (place 114) in Ithaca, NY takes kids on a scale tour of the solar system walking through the town learning about the planets and ends up at the Sciencenter museum which is especially good for kids.

In The Hague, Netherlands there's a museum dedicated to M C Escher which is fun for older children (that's place 029) with optical illusions everywhere.

To find out more you'll need to buy the book.

The Geek Atlas is for non-geeks too

On the back cover of The Geek Atlas there's quote that says: "A great read for geeks and non-geeks alike!" And it's true.

While writing the book I naturally had people like me in mind, but I also had people like my SO who is the anti-geek. She's not interested in how bits of technology work, and scientific topics bore her.

Yet I've dragged her along to a few places in the book. Anyone in a geek/non-geek couple, or parent with a geek child needs to know that they are not going to be bored by either the book or the places in it.

Rest assured. There's plenty to do for the non-geek at geeky sites, and the non-geek might just have a little bit of science rub off on them.

Take place number 051 in the book: Jodrell Bank. The geeks will go to see the Lovell Telescope, but the non-geeks can enjoy it too. Jodrell Bank is set in a bucolic location with a wonderful arboretum to enjoy. And a scale model of the solar system set into the landscape makes an ideal excuse for a walk in the countryside.

Or take a non-geek to place number 071. It's a pub. Geeks will enjoy it because it's the pub in which Crick and Watson announced that they had unraveled the structure of DNA.

If the geeky half of a couple is spending time in London's Science Museum or Natural History Museum (places 077 and 061) then the non-geek might like to spend time in the nearby Victoria and Albert Museum.

And the Eiffel Tower (place number 018) is a great spot for geeks and non-geeks. It's a landmark, looks beautiful and has lots of science to look at and read about.

Non-geek US visitors aren't forgotten. The Computer History Museum (place number 086) is right next to the San Francisco Bay and the Shoreline Park.

The bunker at The Greenbrier (place number 126) is inside a very classy hotel with a wonderful on site spa and extensive recreation facilities. Geeks can even treat the non-geek to a great meal on the restaurant, or make a weekend of it.

And what could be more romantic than a trip to Fairbanks, AK to see the Aurora Borealis?

And then there's the book itself. Each place in the book has a chapter consisting of two parts: a general introduction and a scientific topic related to the place. Non-geeks can skip the science and concentrate on the place and its history. Even my SO was fascinated by the story of Edison and Tesla battling over electricity.

Why I wrote The Geek Atlas

The second most common question about The Geek Atlas (after people have asked me to recommend the one best place to visit) is "Why did you write this book?"

I was working temporarily in Munich and at a loose end one weekend I wandered into the tourist office and asked about things I could see. Munich is a large cultural and industrial city and there's loads of stuff to do and see, but the thing that stood out amongst the tours, churches, beer and gastronomic delights was the Deutsches Museum.

The Deutsches Museum is Germany's science and technology museum and it is, at least in my opinion, the best science museum in the world. It's certainly the largest when you include its two annexes in Munich.

After I'd spent hours and hours wandering the museum's halls and admiring its collection of seemingly everything (including the wonderful jet aircraft that's been sliced Damien Hirst style to reveal its interior) I returned to my hotel.

Sitting in the hotel I realized that I had never heard of this museum. How had I missed out on just the sort of place that excites me? I figured there must be a guide book written by somebody that covers exciting places for people interested in science, mathematics and technology and so I hopped on

I couldn't find a thing.

I surfed around other book sites, and came up with nothing at all. I even visited the sites of specialized travel book companies. Still nothing.

So, I sat down with a fresh emacs buffer and started to type up a list of places that I had visited around the world that I thought would excite other people like me. After an hour of work I had a list of about 70 places.

It was a wonderful hour recalling an afternoon spent in the National Cryptographic Museum, childhood visits to the Science Museum in London, wandering the Arago medallions in Paris, clambering around inside the Computer History Museum when it was just a couple of sheds on Moffett Field, being assaulted by light, noise and technology in Akihabara, keeping a curator way past her lunch time at the Fermat Museum in France, and standing on the wind-swept cliff tops in Poldhu where Marconi transmitted across the Atlantic for the first time.

A little later I had a proposed title: 128 Geeky Places To See Before You Die (if you are a computer geek the number 128 will instantly stand out to you like a secret sign, if you are not you'll have to buy the book to find out why). And I had an idea: write a book where each place is split into two parts.

The first part of each place would be a historical and general description readable by anyone, the second part would be a detailed explanation of the actual science, technology or mathematics behind the place. The general reader could slip the second parts and still enjoy the book.

One year later the book is almost in shops. The reality is that I wrote a book for myself, I wrote the guidebook that I couldn't find. I hope you find it useful (all those places can be visited), informative (I've tried to explain the science in two pages without dumbing it down) and inspiring (even if you don't travel you can dream).

Monday, May 11, 2009

Frequently misunderstood logic: modus tollens

Back when I was in upper school I studied Further Mathematics and one of the topics I loved was logic. We learnt about syllogism and modus ponens, and my favorite modus tollens.

Modus tollens is fun because it is often applied incorrectly in informal arguments to come to the wrong conclusion. Here's an example.

The other day I saw a tweet which read:

"A fear of weapons is a sign of retarded sexual and emotional maturity." - Sigmund Freud, General Introduction to Psychoanalysis (1952)

Simplifying that a little (and assuming we agree with Freud) it can be written "If a person is fearful of weapons, then that person is sexually and emotionally immature". If we write "fearful of weapons" as F and "sexually and emotionally immature" as I, this statement can be rewritten F => I (the => is read as implies and make the entire statement read as F implies I or If F, then I).

So if we come across someone who satisfies F (i.e. they fear weapons) then we know that I applies (i.e. they are sexually and emotionally immature).

Modus tollens tells us that if we come across someone who does not satisfy I (i.e. that person is sexually and emotionally mature) then we know that they do not satisfy F (i.e. they do not fear weapons). Symbolically that would be written ~I => ~F.

Modus tollens tells you that if the "then" side of an "if, then" is false then the "if" side must be also (this has to be the case because the "if, then" forces the "then" side to be true when the "if" side is true).

The common fallacy related to modus tollens is to think that ~F => ~I follows from F => I. That is, given Freud's statement some people will believe that the statement "People who are not fearful of weapons are sexually and emotionally mature". This is called the Denying the antecedent fallacy.

Next time you come across someone who doesn't fear weapons you'll know that Freud tells us nothing about their sexual or emotional maturity.

Resources I used while writing The Geek Atlas

With my book The Geek Atlas about to hit stores I thought I'd blog about some of the resources I used while writing it. With the list of places in hand I had to research both the history of the site and the science behind it. To do that I used many different sources.

Wikipedia and Britannica

My first port of call for information was Wikipedia because it has a very wide range of information, but I was very skeptical about its accuracy and so I bought myself a subscription to Britannica so that I could double check information.

If I read that Boltzmann died in 1906 on Wikipedia I'd jump over to Britannica to check the date. After a few months of doing this I realized that I was never finding inaccurate information on Wikipedia and that my visits to Britannica were a useless time sink.

But worse I noticed a significant difference between Wikipedia and Britannica: Wikipedia was a great starting point for my research, Britannica was a dead end. Because Wikipedia insists that citations are needed for its content, it's possible to start at Wikipedia and quickly find yourself reading original papers that match the Wikipedia article. Or in the worst case you've got a reference to go research in a journal.

For example, in the page on the Miller-Urey experiment to determine how life could have developed on the early Earth, Wikipedia links directly to Miller's 1953 paper describing the results. (I was even able to make a small contribution by correcting a small error after reading the original paper.)

In contrast, Britannica wasn't generous with links off the site. Yes, they do have some references, but their general attitude seems to be "we're Britannica, part of our brand is the assurance that this stuff is accurate". Wikipedia's attitude is "anyone could be making this stuff up, we'd better link to authoritative references". That makes Wikipedia much more useful.

In the end, I canceled my Britannica subscription. Wikipedia proved to be a great index for finding the information I needed.

The Nobel Prize archive

Many of the people I wrote about in the book won Nobel Prizes and the Nobel Foundation has made available the complete texts of the Nobel laureates' speeches freely on their web site.

While researching the work of Cockcroft and Walton, I was able to read Walton's Nobel Prize lecture complete with his diagrams and pictures.

There were many other times I referred to the original lectures given by the Nobel laureates.

The New York Times archive

Although The New York Times is not a primary reference it does contain a large amount of historical material. It's been published since 1851 and its complete archive has been digitized, made searchable, and available for a small fee. I spent $$$ on the New York Times reading news reports of historical events.

For example, the New York Times archive covers the battle between Tesla and Edison over the transmission of electrical current, and has many articles about Nikola Tesla including an account of his funeral.


To get to the bottom of some topics in physics there's the amazing HyperPhysics web site from Georgia State University. The site contains tons of information about physics topics and they were kind enough to let me use some of their diagrams in the book.

If you are interested in understanding bremsstrahlung radiation and its role in producing X-rays then HyperPhysics is a great starting point.

Thank you for this great site made by Rod Nave.


NASA's Jet Propulsion Laboratory and other NASA locations have great web sites detailing the science behind rocket propulsion, flight and other technologies.

For example, NASA's Glenn Research Center has an entire microsite dedicated to explaining rocket physics. The JPL has a good site for understanding Astronomy.

In general, many other US government departments were very helpful. Folks at the US Geological Survey helped out my understanding of the shape of raindrops.

US National Register of Historic Places

The National Register of Historic Places in the US is very helpful because it not only lists places that are of scientific interest, it provides access to the digitized forms filled in when adding a place to the register.

These forms contain a written record of why the site is historic and are utterly fascinating. While researching the Horn Antenna where the Big Bang was confirmed I was able to read the application for entry on the register which contains historical information about its significance.


Many professors around the world received random emails from me asking for assistance in understanding certain scientific topics. All but one of them responded to me (usually within 24 hours) and all of them were very, very helpful.

One of the big problems researching a book like The Geek Atlas is access to scientific papers. Because I wanted to read the original papers for things I was writing about, I needed access to journals. As an individual these are prohibitively expensive: Nature wants $32 to read 700 words written in 1932 about the discovery of the neutron.

Many of these professors freely emailed me PDFs of their papers so that I could read them for free. I am grateful to all of them for assisting me.

To highlight just two people: a big thanks to Patrick Weidman at the University of Colorado at Boulder for helping me understand how the Eiffel Tower's shape is a result of the Parisian wind and David Gordon from the University of Washington for assistance with shotgun DNA sequencing.

Tuesday, May 05, 2009

Can you trust Paul Graham with your password?

The other day I asked Can you trust 37signals with your password? and the good folks at Hacker News responded on their forum and here on my blog. Driving back home the other day I suddenly wondered how good a job Hacker News was doing of keeping my password safe.

The answer is... only marginally better than 37signals. Since the source code of the web site is available it's possible to dig in and find out how Paul Graham handles password authentication.

The good news is that he doesn't store passwords in plain text. And even better he uses a one-way hash function (SHA-1) to verify passwords. When you enter your password it is hashed using SHA-1 (he uses OpenSSL's implementation of SHA-1 to do the hashing) and then stored in a file called arc/hpw. When it comes time to verify a password the hash from the password file is read and compared with a hash of the password you typed in.

(def good-login (user pw ip)
(let record (list (seconds) ip user)
(if (and user pw (aand (shash pw) (is it (hpasswords* user))))
(do (unless (user->cookie* user) (cook-user user))
(enq-limit record good-logins*)
(do (enq-limit record bad-logins*)

(def shash (str)
(let fname (+ "/tmp/shash" (rand-string 10))
(w/outfile f fname (disp str f))
(let res (tostring (system (+ "openssl dgst -sha1 <" fname)))
(do1 (cut res 0 (- (len res) 1))
(rmfile fname)))))

The good news is that this means that if arc/hpw were stolen a hacker wouldn't be able to read the password from the file directly. The bad news is that the file is readily attackable using a rainbow table. If you got access to his password file, the passwords within it (unless they were really, really good passwords) would be broken in seconds or minutes.

That's a pity since he could easily have implemented a salted hash and he would have had a first line of defense against a rainbow table. The current implementation is little better than a plain text password file.

Even better he could have swapped SHA-1 for a slow algorithm like bcrypt. With salted bcrypt rainbow tables are out of the window, as are password crackers that rely on running a dictionary plus salt through the hash algorithm.

Friday, May 01, 2009

Can you trust 37signals with your password?

Recently, 37signals blogged touting their security in dramatic marketing terms. It's a pity that the reality doesn't match the claims.

Two of the major claims on the security page are Your data won’t be compromised and Our systems are hacker safe. And the related details talk about the firewalling and physical security of their data center. All that's great.

But there's a dirty little secret. 37signals stores passwords in plain text in their database (or, as commentators have pointed out, they could be storing the password encrypted using a key available to their application server; either way the password can be recovered by a hacker who gains access to their server). I found this out today when cancelling my Highrise account. I'd forgotten the password and so I went through password recovery. It instantly emailed me my password.

I'd expected to receive a temporary password and be asked to change it. But 37signals stored my password in their database and was happy to email it out. For me this isn't a disaster because I generate unique passwords for each registration, but for lots of people this is a big problem. Plenty of people use the same password on many different sites.

That means if one site is compromised hackers can get access to all those user's other accounts. And a compromise can come in various forms. It could be actually hacking into 37signals, or it could be getting access to an old backup of their database.

But there's a solution to this, it's easy to implement, it completely eliminates the problem even if their site is hacked, and it's a security best practice. There are plenty of good descriptions of how to implement it. The Unix operating system has been doing this since the 1970s, so why is 37signals not doing it? Hard to tell.

In a posting in 2007, Jason Fried said that they planned to change this, but now it's 2009.

There's no excuse for this sort of lax security, if 37signals got hacked they'd have to bow their heads in shame in front of every single one of their customers and admit that their password had been stolen. Why take the risk?